1. Field
Apparatuses consistent with exemplary embodiments relate to apparatuses for recording and reproducing holograms, and more particularly, to apparatuses for recording and reproducing holograms having a compact structure.
2. Description of the Related Art
Holography is a technology whereby an interference pattern between a signal beam containing a signal and a reference beam is recorded to reproduce the signal as a stereoscopic image. Holography may be used in various fields such as the recording and reproduction of stereoscopic images, the prevention of forgery and the verification of genuine articles, or the recording and reproduction of digital data. In addition, fine interference patterns may be recorded on a flat photosensitive recording film in units of pixels, so a three-dimensional image may be viewed on a two-dimensional plane. Micro-holographic technology is currently being commercialized.
Micro-holograms may be classified as rear projection micro-holograms or reflective micro-hologram. A rear projection micro-hologram is a stereoscopic image formed by light that has been transmitted through a recording film, and a reflective micro-hologram is a stereoscopic image formed by light that has been reflected off a recording film. In particular, a reflective micro-hologram may be used to record/reproduce full-color or full-parallax images and may represent gradation.
Typically, a micro-hologram may be recorded by dividing a beam emitted from a light source into a signal beam and a reference beam, modulating the signal beam, and irradiating the signal beam and the reference beam on the same location on a photosensitive recording film. The signal beam may be modulated by using a spatial light-modulator according to an interference pattern calculated by a computer based on an image that is to be finally reproduced from the photosensitive recording film.
A small holographic printing apparatus is essential in order to implement a home or office holographic printing apparatus to which such a hologram recording technology may be applied